CXA2550M/N
RF Amplifier for CD Players
Description
The CXA2550M/N is an IC developed for compact
disc players. This IC incorporates an RF amplifier,
focus error amplifier, tracking error amplifier, APC
circuit and RF level control circuit. (The voltage-
converted optical pickup output is supported.)
Features
•
•
•
•
Low power consumption (35mW at 3.5V)
APC circuit
RF level control circuit
Both single power supply and dual power supply
operations possible.
Structure
Bipolar silicon monolithic IC
Applications
Compact disc players
Block Diagram and Pin Configuration
(Top View)
18 AGCCONT
(50%/30%/OFF)
CXA2550M
20 pin SOP (Plastic)
CXA2550N
20 pin SSOP (Plastic)
Absolute Maximum Ratings
(Ta = 25°C)
12
•
Supply voltage
V
CC
•
Operating temperature Topr
–20 to +75
•
Storage temperature
Tstg
–65 to +150
•
Allowable power dissipation
P
D
(SOP)
620
V
°C
°C
mW
mW
(SSOP) 370
Operating Conditions
Supply voltage
V
CC
– V
EE
3.0 to 4.0
V
19 LD_ON
15 RF O
14 RFM
13 FE
12 FE_BIAS
17 RFTC
16 RF I
20 V
CC
V
CC
174k
11 TE
30k
30k
30k
VC 10
49
96k
VC
15k
V
EE
TRACKING
ERROR
VC AMP
VC
V
CC
15k
6k
54k
13.4k
50µA
670mV
V
EE
154k
FOCUS
ERROR
AMP
87k
32k
13k
32k
24p
VC
260k
8
E
VC
VC
VC
F
7
26k
12p
12p
13k
24p
56k APC LD
AMP
56k
10k
VC
2k
10k
10k
1k
V
CC
55k
V
EE
VREF 1.25V
VC
2k
APC PD AMP
8k 6p
2k
8k 6p
10k
10k
V
EE
10k
VC VC
2
5
VC
V
EE
VC
VC
260k
2k
25k
1
4
3
6
PD1
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
AGCVTH
PD2
–1–
V
EE
LD
PD
EI
9
V
CC
30k
95k
E97514B25
CXA2550M/N
Pin Description
Pin
No.
Symbol
I/O
Equivalent circuit
Description
50µ
147
1
AGCVTH
—
1
13.4k
10µ
Reference level variable pin for RF
level control.
The reference level can be varied by
the external resistor.
10k
2
LD
O
2
1k
APC amplifier output pin.
20µ
8µ
3
PD
I
147
3
55k
10k
APC amplifier input pin.
10k
4
5
PD1
PD2
I
I
4
5
100µ
Inversion input pin for RF I-V
amplifiers.
Connect these pins to the
photodiodes A + C and B + D
respectively. The current is supplied.
6
V
EE
—
6
V
EE
V
EE
pin.
–2–
CXA2550M/N
Pin
No.
Symbol
I/O
Equivalent circuit
12p
260k
Description
7
8
F
E
I
I
7
8
10µ
Inversion input pin for F and E I-V
amplifiers.
Connect these pins to the
photodiodes F and E respectively.
The current is supplied.
13k
26k
9
EI
—
147
9
260k
Gain adjustment pin for I-V amplifier.
V
CC
V
CC
200µ
10
VC
O
10
50
120
15k
120
16k
DC voltage output pin of
(Vcc + V
EE
)/2.
Connect to GND for ±1.75 power
supply; connect a smoothing
capacitor for single +3.5V power
supply.
V
EE
11
TE
O
11
96k
300µ
Tracking error amplifier output pin.
E-F signal is output.
–3–
CXA2550M/N
Pin
No.
Symbol
I/O
Equivalent circuit
Description
32k
164k
12
12
FE_BIAS
I
24p
174k
10µ
Bias adjustment pin for inverted side
of focus error amplifier.
24p
13
FE
O
13
174k
300µ
Focus error amplifier output pin.
2k
2k
147
14
RFM
I
14
850
1m
RF amplifier inverted side input pin.
RF amplifier gain is determined by
the resistor connected between this
pin and RFO pin.
15
RF O
O
147
15
60k
1m
RF amplifier output pin.
–4–
CXA2550M/N
Pin
No.
Symbol
I/O
Equivalent circuit
Description
147
16
16
RF I
I
15k
The RF amplifier output RFO is input
with its capacitance coupled.
20µ
17
RFTC
—
147
17
50µ
50µ
External time-constant pin for RF
level control.
10µ
15µ
147
15µ
18
AGCCONT
I
18
50k
7µ
RF level control ON (limit level of
50%/30%)/OFF switching pin.
OFF for Vcc, 30% for open or Vc
and 50% for V
EE
.
50µ
147
19
LD_ON
I
19
V
REF
APC amplifier ON/OFF switching
pin.
OFF for Vcc and ON for V
EE
.
20
V
CC
20
V
CC
Vcc pin.
–5–
京公网安备 11010802033920号
EEWORLD
